Skip over navigation
Cambridge University Faculty of Mathematics NRich logo
menu search
  • Teachers expand_more
    • Early years
    • Primary
    • Secondary
    • Post-16
    • Events
    • Professional development
  • Students expand_more
    • Primary
    • Secondary
    • Post-16
  • Parents expand_more
    • Early Years
    • Primary
    • Secondary
    • Post-16
  • Problem-Solving Schools
  • About NRICH expand_more
    • About us
    • Impact stories
    • Support us
    • Our funders
    • Contact us
  • search

Or search by topic

Number and algebra

  • The Number System and Place Value
  • Calculations and Numerical Methods
  • Fractions, Decimals, Percentages, Ratio and Proportion
  • Properties of Numbers
  • Patterns, Sequences and Structure
  • Algebraic expressions, equations and formulae
  • Coordinates, Functions and Graphs

Geometry and measure

  • Angles, Polygons, and Geometrical Proof
  • 3D Geometry, Shape and Space
  • Measuring and calculating with units
  • Transformations and constructions
  • Pythagoras and Trigonometry
  • Vectors and Matrices

Probability and statistics

  • Handling, Processing and Representing Data
  • Probability

Working mathematically

  • Thinking mathematically
  • Developing positive attitudes
  • Cross-curricular contexts

Advanced mathematics

  • Decision Mathematics and Combinatorics
  • Advanced Probability and Statistics
  • Mechanics
  • Calculus

For younger learners

  • Early Years Foundation Stage

Paper Halving

Age 5 to 11
Challenge Level Yellow star
  • Problem
  • Student Solutions
  • Teachers' Resources

Paper Halving




In how many different ways can you halve an A4 sheet of paper?

You might start off with something like these two, for example:


Have a good explore and see what different ways you can find. Don't be afraid to be creative!

How will you know if they are halves?
 


Why do this problem?

This activity offers free exploration that can help youngsters with their development of the concepts associated with fractions.  It provides a chance for meaningful mathematical discussion and sharing of current understanding, in addition to offering opportunities for challenging misconceptions.


Possible approach

This task is best introduced as succinctly as possible so that learners have the freedom to work in any way they wish. Make sure that pupils know that they have a choice in how they fold/cut/draw to show halves - the key is that they can justify that the two parts really are halves. 

Here are some ways of halving that sometimes occur:


(Please note that the labelling of A and B is ours, not the children's.)  

Some learners may be adventurous and use curves such as these, which produce interesting justifications as to how they are halves:



Talk is key for this task.  Asking children to explain their ideas will help to reveal their understanding even if their constructions are not quite accurate.  You can facilitate discussion about not all halves being symmetrical and it would also be fruitful to ask how learners think the task would have been affected if they had been given squared paper rather than plain.


Key questions

Tell me about your halves.
How do you know this is a half?
Can you find some other ways of halving the paper?

Possible extension

Repeat the same for thirds. (Yes thirds before quarters!)
 

Possible support

There may be some pupils who need support folding, cutting and/or drawing as well as any measuring.  It might be appropriate to pair children with different skills in this regard.

You may also like

Pizza Portions

My friends and I love pizza. Can you help us share these pizzas equally?

A Bowl of Fruit

Can you work out how many apples there are in this fruit bowl if you know what fraction there are?

Doughnut

How can you cut a doughnut into 8 equal pieces with only three cuts of a knife?

  • Tech help
  • Accessibility Statement
  • Sign up to our newsletter
  • Twitter X logo

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

University of Cambridge logo NRICH logo